1. Field of the Invention
The invention relates to cooling agent compositions that impart a cooling sensation to the skin and mucous membranes of the body, particularly the mouth, nose, throat and gastrointestinal tract during consumption and methods for making cooling agents. The cooling agents comprise N-substituted p-menthane-3-carboxamides, menthyl acetate and a solubilizer, in spray dried form. The invention also concerns pharmaceutical compositions comprising the cooling agents, including tablets, suspensions and liquid solutions having active ingredients for treating upper gastrointestinal tract distress, and methods for treating upper gastrointestinal tract distress in humans. The cooling agents may also be used in a sundry of edible products such as confectionary products, including chewing gum, hard and soft candies and the like.
2. The Prior Art
Cooling agents and compositions are used in a sundry of consumer goods. U.S. Pat. No. 4,136,163 describes the use of N-substituted p-menthane-3-carboxamides in edible and potable compositions, toiletries, medicaments, and miscellaneous compositions such as envelopes, postage stamps and adhesive compositions. The N-substituted p-menthane-3-carboxamides are described as having a physiological cooling effect on the skin and on the mucous membranes of the body, particularly the mouth, nose, throat and gastrointestinal tract. U.S. Pat. No. 4,060,091 describes the use of N-substituted p-menthane-3-carboxamides in tobacco or tabacco containing products.
In pharmaceutical compositions, such as antacids, useful for treating upper gastrointestinal tract distress, such as heartburn, indigestion, stomachache and the like, cooling agents are generally employed as excipients to provide cooling sensation when the pharmaceutic composition is consumed. Generally, the active pharmaceutical agent in pharmaceutical compositions for treating upper gastrointestinal tract distress will not immediately begin to relieve the condition causing the distress. Cooling agents, used in the pharmaceutical compositions as excipients, however, provide cooling sensation to the mouth, throat and gastrointestinal tract so that the pharmaceutical composition will be perceived by the consumer as acting faster to alleviate the gastrointestinal distress. Thus, the consumer is provided with the sensation of relief although the active principle of the pharmaceutical composition has not begun to alleviate the conditions causing the distress.
U.S. Pat. No. 5,244,670 describes ingestible pharmaceutical compositions for treating upper gastrointestinal tract distress comprising active principle and 3,1-methoxy propane 1,2-diol (xe2x80x9cMPDxe2x80x9d). U.S. Pat. No. 5,009,893 describes chewing gum compositions comprising a cooling agent having from about 5% to about 70%, by weight, of menthol and from about 30% to about 95%, by weight, of N-substituted p-menthane-3-carboxamide compounds. The combination of the menthol and the carboxamide compounds in the amounts specified in U.S. Pat. No. 5,009,893 are said to be necessary for cooling and breath freshening properties. U.S. Pat. No. 5,698,181 describes breath-freshening edible compositions comprising a cooling composition of essential ingredients of about 94% to about 99.999%, by weight, menthol and about 0.001% to about 6%, by weight, N-substituted p-menthane-3-5 carboxamides.
There is a consumer demand, and consequently a need, for cooling agents that provide faster cooling sensation when consumed and longer lasting effect. The art of cooling agents for pharmaceutical compositions, confectionary products and like comestibles is constantly evolving.
It was an object of the invention to develop new cooling agents for use in comestible goods, like pharmaceutical compositions, and confectionary products, like gum, that provide cooling effect and long lasting freshness.
We have discovered that cooling agents comprising the combination of N-substituted p-menthane-3-carboxamides, menthyl acetate and solubilizer, in spray dried form, act synergistically to provide cooling sensation and a long lasting freshness effect. The cooling agents are particularly useful in pharmaceutical compositions for treating upper gastrointestinal tract distress.
In the present Specification, all parts and percentages are by weight/weight unless otherwise specified. The term xe2x80x9cby weight of cooling agent componentsxe2x80x9d as used herein means the weight percentage based on the total weight of all of the components of the cooling agent, such as the carboxamide, menthyl acetate and solubilizer. The term xe2x80x9cby weight of the combinationxe2x80x9d as used herein means the weight percentage based on the total weight of all of the components of the cooling agent and the carrier and residual water in the spray dried particles. The term xe2x80x9cby weight of the pharmaceutical compositionxe2x80x9d as used herein means the weight percentage based on the total weight of all components of the pharmaceutical composition.
The invention pertains to cooling agents comprising N-substituted p-menthane-3-carboxamides, menthyl acetate and a solubilizer. The finished cooling agent is in spray dried form and, in that state, can be used in a number of products, including pharmaceutical compositions, particularly those for treating upper gastrointestinal tract distress, and confectionary products. The menthyl acetate is combined with the N-substituted p-menthane-3-carboxamides and the combination acts synergistically to provide the cooling effect and long lasting freshness that characterizes the invention.
The N-substituted p-menthane-3-carboxamides, menthyl acetate and solubilizer can be made through spray drying processes. For example, the cooling agent can be combined with a carrier and water to form an emulsion for spray drying to obtain spray dried particulate material comprising the cooling agent and a carrier. The solubilizer in the cooling agent prevents the N-substituted p-menthane-3-carboxamides from crystallizing out of solution during the spray drying process, which requires heat to maintain solubility.